China's manned submersible, the Jiaolong, returns to the deck of the Xiangyanghong 09 research ship after its fourth dive into the Mariana Trench in the Pacific Ocean, June 24, 2012. The Jiaolong, named after a mythical sea dragon, succeeded in diving 7,020 meters below sea level during its fourth dive here on Sunday. (Xinhua/Luo Sha)